In addition to this issue with Netflix, I've also found that I've had to re-enter ID & password recently for Pandora.. It is annoying; but will be easier in the future now that I've received the Slide Pro remote...

I have had it lose my login info on both my Roamio and my Mini. Makes more sense that there was some sort of update to each, but that really is annoying...and I don't think the same thing happens on PS3 when it updates that app.

For what it's worth, I've had a Roamio Basic (OTA) and two Minis since November, and I use Netflix almost daily on all of them, and I have never had to re-enter my password. Perhaps the issue only affects the pro model and can be fixed with a software update of some kind. You might want to make sure that the issue has been reported to the TiVo support folks.